Mondo Description Postorgasmic illness syndrome (POIS) is a rare condition in which a man develops flu-like symptoms after ejaculation (when semen is released from the penis). Specific symptoms can include extreme fatigue, weakness, feverishness or sweating, mood changes or irritability, memory or concentration problems, and/or a stuffy nose or itching eyes. Symptoms may occur within seconds, minutes, or a few hours after ejaculation. Most symptoms last for 2 to 7 days and go away on their own. The underlying cause of POIS is poorly understood. Some scientists believe it may be due to a semen allergy that causes an immediate hypersensitivity reaction. There is no standard treatment for POIS, but some men have been treated with SSRIs, antihistamines, and/or benzodiazepines. Hyposensitization therapy (decreasing the immune response by exposure to semen) reportedly improved symptoms in two men with POIS.